Atezolizumab may be a safe and effective option for patients with non-small cell lung cancer (NSCLC) who have progressed on post-platinum chemotherapy, according to results from a phase 2 randomized controlled trial.
Atezolizumab is part of a new class of immunotherapy drugs that inhibit the interaction of programmed death ligand 1 (PD-L1) and programmed cell death protein 1, a mechanism believed to be the means by which many cancerous cells avoid detection from the body’s immune system. Results of prior trials involving atezolizumab showed that it was successful at shrinking tumor size and improving survival compared to other standards of care.
Results published in The Lancet expanded on data from the POPLAR (atezolizumab versus docetaxel for patients with previously treated non-small-cell lung cancer) clinical trial, evaluating the efficacy and safety of atezolizumab compared with docetaxel in patients with NSCLC who progressed on post-platinum chemotherapy by analyzing their PD-L1 expression levels on tumor cells and tumor-infiltrating immune cells in the intention–to-treat-population of the study.
A total of 287 patients were recruited from academic medical centers and community oncology practices across 13 countries in Europe and North America and randomly assigned to receive atezolizumab (n=144) or docetaxel (n=143) once every 3 weeks. Baseline PD-L1 expression was scored by immunohistochemistry in tumor cells and tumor-infiltrating immune cells with the primary endpoint being overall survival. Safety in all patients who received at least 1 dose of the study drug was also assessed.
Overall survival was found to be significantly higher in the group receiving atezolizumab (12.6 months) compared with the docetaxel group (9.7 months). Additional analysis also revealed that overall survival improved as PD-L1 expression levels increased, suggesting that the drug would be most effective for patients whose tumors express more PD-L1.
Atezolizumab also appeared to be the safer option for patients in the trial. Only 11 (8%) of patients in the atezolizumab group had to discontinue treatment due to adverse events compared with 30 (22%) patients in the docetaxel group. In addition, patients receiving atezolizumab had fewer grade 3-4 adverse events (16; 11%) than those being treated with docetaxel (52; 39%), and only 1 (<1%) patient taking atezolizumab versus 3 (2%) patients taking docetaxel died from a treatment-related adverse event.
Investigators concluded that atezolizumab significantly improved the survival of previously treated patients with advanced or metastatic NSCLC versus docetaxel with a safety profile that was well-tolerated and distinct from chemotherapy.
